The present invention relates to a battery packet, and a battery case forming sheet for forming a battery case for containing the component elements of a battery.
Most conventional battery cases for containing the component elements of a battery are metal cases. Various electronic apparatuses including notebook computers and portable telephone sets have been developed and have diffused, and efforts have been made in recent years to reduce the weight and thickness of such electronic apparatuses. Demand for the development of lightweight, thin batteries requiring less space has increased with the progressive reduction in the weight and thickness of such electronic apparatuses.
To meet such a demand, activities have been made for the research and development of various lightweight, thin sheet batteries using electrodes and electrolytes of polymeric materials. Nevertheless, any light, thin battery cases for sheet batteries, satisfying all requisite properties including strength, moisture- and gas-impermeability, sealing performance and adhesion to electrodes and terminals have not been provided.
The present invention has been made in view of the foregoing problems and it is therefore an object of the present invention to provide a light, thin sheet for lightweight, thin battery cases, having excellent properties in strength, durability, moisture and gas impermeability, sealing and adhesion to electrodes and terminals, and capable of being easily processed, and to provide a battery packet.
The present invention provides a battery case forming laminated sheet for forming a battery case comprising a first base film, and a heat-adhesive resin layer formed on the inner side of the first base film,
a battery packet comprising a battery, a battery case containing the battery, and tabs connected to the battery and projecting outside from the battery case, and
a battery packet comprising a battery, tabs connected to the battery, and a battery case containing the battery and the tabs, in which a peripheral part of the battery case is sealed, and recesses are formed in parts of the sealed peripheral part corresponding to the tabs.